zfs initialize performance enhancements
ZoL commit c10d37dd9f5
When invoking "zpool initialize" on a pool the command will
create a thread to initialize each disk. Unfortunately, it does
this serially across many transaction groups which can result
in commands taking a long time to return to the user and may
appear hung. The same thing is true when trying to suspend/cancel
This change refactors the way we invoke the initialize interface
to ensure we can start or stop the intialization in just a few
When stopping or cancelling a vdev initialization perform it
in two phases. First signal each vdev initialization thread
that it should exit, then after all threads have been signaled
wait for them to exit.
On a pool with 40 leaf vdevs this reduces the vdev initialize
stop/cancel time from ~10 minutes to under a second. The reason
for this is spa_vdev_initialize() no longer needs to wait on
multiple full TXGs per leaf vdev being stopped.
This commit additionally adds some missing checks for the passed
"initialize_vdevs" input nvlist. The contents of the user provided
input "initialize_vdevs" nvlist must be validated to ensure all
values are uint64s. This is done in zfs_ioc_pool_initialize() in
order to keep all of these checks in a single location.
Updated the innvl and outnvl comments to match the formatting used
for all other new sytle ioctls.